JPH0642363B2 - Display tube for light source - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a large-screen display device, and more particularly to a light source display tube which constitutes a pixel of a color display device.

[Prior art]

When a large-screen display device is configured by arranging single-color display tubes using the light emission of the phosphor as one pixel in a matrix, a space is formed in the connection portion of each single-color display tube, and it is difficult to improve the resolution. Higher resolution may result in higher cost. Therefore, conventionally, a composite type light source display tube disclosed in, for example, Japanese Patent Laid-Open No. 62-10849 has been proposed. 4 and 5 are a front view and a sectional view taken along line VV of the basic structure of the composite type light source display tube, and FIG. 6 is an exploded perspective view of a part thereof, in which R (red) is shown. , G (green)
2 shows the case where the phosphor screens each having one of the B and blue (B) phosphors as one pixel are arranged in a matrix of 3 × 3 pixels. In these figures, reference numeral 1 denotes a vacuum envelope as a glass tube which is hermetically sealed by a front panel 2, a back plate 3 and a tubular side plate 4, and an inner surface of the front panel 2 has a three-color phosphor. Each of R, G and B is applied as a unit pixel in a matrix and arranged in a matrix to form 3 × 3 pixel phosphor screens 5R, 5G and 5
A fluorescent display portion 5 made of B is formed. Here, the suffixes of the phosphor screens 5R, 5G and 5B correspond to red (R), green (G) and blue (B), respectively. Reference numeral 6 denotes an anode electrode group composed of a plurality of accelerating anodes 6 ₁ , 6 ₂ , ... Arranged correspondingly around the respective fluorescent screens 5R, 5G and 5B of the fluorescent display unit 5, and these accelerating electrodes are A high voltage is applied to the anodes 6 ₁ , 6 ₂ , ... Via the external terminal 16. Reference numeral 7 corresponds to each of the fluorescent screens 5R, 5G, 5B of the fluorescent display unit 5 and cathodes for electron emission 7 _{11 to} 7 ₃₃ (cathodes 7 ₃₁ , 7).
₃₃ is a cathode electrode group in which (not shown) are independently arranged. These cathodes 7 _{11 to} 7 ₃₃ have a pair of supports 17a, 17 having both ends fixed on the back plate 3.
It is supported between b. Here, the first and second subscripts of the cathodes 7 _{11 to} 7 ₃₃ are the first to third rows and the first to third rows, respectively.
Corresponds to the column. Note that the cathodes 7 _{11-7 33,} for example, a straight thermal coated with oxide oxide coated indirectly heated or tungsten on the Ni sleeve can be used. Further, 8 is a grid electrode group including control grids 8 ₁ to 8 ₃ for row selection arranged between the cathode electrode group 7 and the fluorescent display portion 5, and these control grids 8 ₁ to 8
₃ includes fluorescent screens 5R, 5G and 5B of the fluorescent display unit 5.
Correspondingly, electron passing holes 9 _{1 to} 9 ₃ are provided in the row direction to pass the electron beams 11 from the cathodes 7 _{11 to} 7 ₃₃ as non-focused beams, respectively. Reference numeral 10 denotes the rear surface side of the cathode electrode group 7, that is, on the rear plate 3 forming a part of the vacuum envelope 1, in the column direction corresponding to the respective fluorescent screens 5R, 5G and 5B of the fluorescent display portion 5. Is a back electrode group including back electrodes 10 ₁ to 10 ₃ for column selection in stripes, which are arranged to face each other. The back electrodes 10 ₁ to 10 ₃ are formed of a conductor layer of Ag or the like. Then, each of the back electrodes ₁₀ 1 to 10 _3, by applying a positive potential of the negative and 0V or several V relative to the potential of the cathode 7 _{11-7 33,} which cathode 7 _{11-7 33}
The electron beam 11 emitted from is controlled. Reference numeral 12 is a lead wire as an external terminal for drawing out each electrode of the cathode electrode group 7, the grid electrode group 8 and the back electrode group 10 from the back plate 3. Next, the operation will be described. First, the back electrode ₁₀ 1 -
10 When ₃ is a negative potential with respect to the potential of the cathode 7 _{11-7 33,} because around these cathode 7 _{11-7 33} is surrounded by a negative potential, electrons are controlled from the cathode 7 _{11-7 33} grid ₈ 1-8 ₃ and acceleration anode _{6 1, 6} 2,
It does not flow to ……… and enters the cutoff state. Therefore, the cathodes 7 ₁₁ to the rear electrodes 10 ₁ to 10 ₃
When applying a positive potential of 0V or several V with respect 7 ₃₃ potential, electrons flow beam 11 emitted from the cathodes 7 _{11-7 33} toward the control grid ₈ 1-8 _3. At this time, when the potentials of the respective control grids 8 ₁ to 8 ₃ are negative with respect to the cathodes 7 _{11 to} 7 ₃₃ , the electron passage holes 9 _{1 to} 9 _{3 of} these control grids 8 ₁ to 8 ₃ are used. The electron beam 11 cannot pass therethrough, and the acceleration anodes 6 ₁ , 6 ₂ , ...
The electron beam 11 does not flow to the respective fluorescent screens 5 of the fluorescent display unit 5.
R, 5G, and 5B do not emit light. Then, the potentials of the control grids 8 ₁ to 8 ₃ are set to the cathode 7 ₁₁
When the potential is positive with respect to ~ 7 ₃₃ , these control grids 8
_The electron beam 11 is emitted from the electron passage holes 9 _{1 to} 9 _{3 of 1} to 8 _3.
Respectively pass through and cause each of the fluorescent surfaces 5R, 5G, and 5B to emit light. Therefore, the control grids 8 ₁ to 8 _{3 of} the grid electrode group 8 and the back electrodes 10 ₁ to 10 _{3 of the} back electrode group 10 arranged in a matrix corresponding to the phosphor screens 5R, 5G, and 5B are respectively provided. By selectively driving and controlling (dynamically driving) the fluorescent screen 5 where the two electrodes intersect.
Only R, 5G, and 5B can selectively emit light. As described above, the phosphor screens 5R, 5G, and 5B made of phosphors of three colors are arranged in a matrix of 3 × 3 pixels on the inner surface of the front panel 2 which constitutes the vacuum envelope 1, and each of these phosphor screens is arranged. By providing the cathode electrode group 7, the grid electrode group 8, and the back electrode group 10 corresponding to 5R, 5G, and 5B, a display tube for a light source of high brightness light emission can be obtained. Therefore, when a large-screen color display device is assembled by using this light source display tube as one cell, the space between each pixel becomes narrower and the resolution can be improved as compared with the case where a single color tube having one pixel is used. With
The number of parts and the number of manufacturing steps can be reduced. Further, not only the structure can be simplified and the cost can be reduced, but also the weight of the display device can be reduced. In the illustrated example, R, G and B are formed on the inner surface of the front panel 2.
Although the case where the phosphor screens composed of the three-color phosphors are arranged in a matrix of 3 × 3 pixels is shown, the invention is not limited to this, and one phosphor is defined as one pixel in the vacuum envelope. It is also possible to arrange the phosphor screens in a matrix of arbitrary m × n pixels (where m and n are arbitrary integers) and change the arrangement configuration of the grid electrode group and the back electrode group accordingly.

[Problems to be Solved by the Invention]

Since the conventional display tube for a light source is configured as described above, the contrast may be lowered due to the influence of external light (for example, sunlight) on the fluorescent screen. Therefore, as shown in FIG. 7, filters 13R, 13G, and 13B are provided on the surface of the front panel, corresponding to the fluorescent screens and transmitting only the light of the color emitted by the fluorescent screens to reduce the influence of external light. We are trying to improve the contrast. However, the light emitted from the fluorescent screen also passes through the filter and is reduced, which may reduce the emission brightness. The present invention has been proposed in view of the above, and an object of the invention of claim 1 is to obtain a display tube for a high-luminance light source that secures a horizontal viewing angle and makes it easy to see a displayed image. . Another object of the present invention is to obtain a light source display tube capable of displaying a high-contrast image.

[Means for Solving the Problems]

In the display tube for a light source according to the invention described in claim 1, a condenser lens provided on the surface of the front panel constituting the vacuum envelope so as to correspond to the phosphor screen is used. It is formed smaller. In the light source display tube according to the second aspect of the present invention, a filter that transmits only the light of the color emitted by the corresponding fluorescent screen is disposed between the condenser lens and the front panel surface.

[Action]

In the condenser lens according to the first aspect of the present invention, the vertical radius of curvature is made smaller than the horizontal radius of curvature, so that the horizontal viewing angle can be secured, and the brightness can be improved. The filter according to the second aspect of the present invention transmits only the light of the color emitted by the corresponding phosphor screen, thereby preventing the influence of external light on the phosphor screen and displaying a high-contrast image.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a part of a light source display tube according to the present invention, and FIG.
The figure is a sectional view taken along the line II-II, and FIG. 3 is the section III-III.
It is sectional drawing which follows the line. In FIGS. 1 to 3, in which the same parts as those in FIG. 7 are designated by the same reference numerals, 14 is a convex lens as a condenser lens which is adhered and fixed to the front surface of each filter 13R, 13G, 13B with a transparent adhesive or the like. . The convex lens 14 has a radius of curvature in the vertical direction (Y-axis direction) smaller than that in the horizontal direction (X-axis direction), and the effective lens diameter thereof enhances the lens effect.
It is larger than G and 5B to cover the dead zone of the phosphor screen. The filters 13R, 13G, and 13B are, for example, printed,
It is formed on the surface of the front panel by means such as coating. Therefore, the respective color lights emitted from the fluorescent screen pass through the filters 13R, 13G and 13B, respectively, and enter the convex lens 14, and are condensed by the convex lens 14 to have high brightness in the front (display) direction. Moreover, since the front shape of the convex lens 14 is an aspherical surface and the radius of curvature in the vertical direction is smaller than the radius of curvature in the horizontal direction, the viewing angle in the horizontal direction can be secured.

【The invention's effect】

As described above, according to the first aspect of the invention, the condensing lens having the vertical radius of curvature smaller than the horizontal radius of curvature corresponds to the fluorescent surface on the front panel surface constituting the vacuum envelope. Since it is provided as described above, there is an effect that the viewing angle in the horizontal direction is secured, the displayed image is easy to see, and the display brightness is increased. Further, according to the invention described in claim 2, since the filter which transmits only the light of the color emitted by the corresponding fluorescent screen is arranged between the condenser lens and the front panel surface, the influence of external light on the fluorescent screen is provided. This is effective in preventing an image display with high contrast.

[Brief description of drawings]

1 is a front view of a portion of a light source display tube according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is line III-III in FIG. 4 is a front view of a conventional light source display tube, FIG. 5 is a cross-sectional view taken along line VV of FIG. 4, FIG. 6 is an exploded perspective view of a part thereof, and FIG. The figure is a perspective view showing the relationship of the filter to the fluorescent surface of the front panel. 1 is a vacuum envelope, 2 is a front panel, 3 is a back plate, 4 is a cylindrical side plate, 5R, 5G and 5B are fluorescent screens, 6 is an anode electrode group,
7 is a cathode electrode group, 8 is a grid electrode group, 10 is a back electrode group, 13R, 13G and 13B are filters, and 14 is a convex lens (condensing lens).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Iwata 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Sanryo Electric Co., Ltd. Applied Equipment Research Laboratory (56) Reference JP-A-62-172646 (JP, A) ) Actual public Sho 61-31349 (JP, Y1)

Claims (2)

[Claims] 1. A display unit in which a plurality of fluorescent screens are arranged in a matrix with a fluorescent screen formed on an inner surface of a front panel constituting a vacuum envelope as one pixel, and a flow of an electron beam irradiated to the fluorescent screen is controlled. , A light emission control unit for controlling the light emission of the phosphor screen,
A condenser lens is provided on the front panel surface corresponding to each of the fluorescent screens. The condenser lens covers the fluorescent screen and has a vertical radius of curvature smaller than a horizontal radius of curvature. A display tube for a light source characterized by: 2. The display tube for a light source according to claim 1, further comprising a filter disposed between the condenser lens and the front panel surface, the filter transmitting only the light of the color emitted by the corresponding fluorescent screen.